Personal Firewalls

As this information is aimed at the home user with a broadband or dial-up modem connection only I will only deal with Personal Firewalls here.

There are two basic types of firewalls: software firewalls and hardware firewalls.

A software firewall resides on the computer itself and monitors all of incoming and outgoing traffic on that computer.

A hardware firewall is a device that is connected between the Internet and your computer. These devices are often used in small network environments where several computers need to share the same Internet connection. The small routers that many people use in their offices and homes usually have built-in firewalls. Both types of firewalls can keep the attackers from gaining unwanted access to your computer.

Do you need a Firewall?

If you are running Windows XP with Service Pack 2 you already have a basic firewall but if you are serious about the security of your computer you should consider upgrading to something more effective.

The latest research shows that a typical unprotected PC will come under attack within 10-15 minutes of being connected to the Internet. In fact the situation is so bad that a newly connected PC won't have time to update it's antivirus program or even to download all the Windows update patches needed to make it secure, before malicious software has found and infected it.

A personal computer connected to the internet can be compared to a house in a bad neighbourhood, with all it's doors & windows open. Having an up-to-date antivirus program is the equivalent of locking the doors, but even an amateur burglar will get in through an open window. A personal firewall gives a computer the added protection of a "deadlock" on the doors and bolts on the windows.

An antivirus program and a firewall are complementary to each other, but whereas most antivirus programs can still do an adequate job with their default settings, any firewall worth having must be customized. An improperly configured firewall will either provide inadequate protection or hamper legitimate activities.

What a Firewall does and what it doesn't

Don't make the mistake of buying a firewall and thinking your security problems are solved. Firewalls may be great at stopping unwanted intrusions, but they often do little or nothing to detect virus-laden e-mails or stop intrusive adware and spyware. You'll want separate antivirus and spyware checkers to deal with these threats (refer to the relevant pages on my site for information about these).

It should be noted that the firewall included in Windows XP Service Pack 2 does not manage outbound traffic, which means a piece of spyware can freely send data from your PC to a server on the Internet.

What do hardware firewalls do?

Primarily they block inquisitive software that probes and queries IP addresses in the hopes of finding a wide-open system. Software firewalls also detect which applications are trying to send data over the Internet and prompt users to allow or disallow the activity.

So when a previously unknown program asks for Internet access, you will be asked to confirm whether the application is actually spyware or a legitimate program. A good firewall (such as Zone Alarm - see side panel) will have adjustable alert levels so you can flag every access for review or simply allow all traffic through by default.

If you already have a firewall and want to test its effectiveness, go to the ShieldsUp port test service at Steve Gibson's Web site, where you can perform a comprehensive scan of all the ports at your IP address. The scan will take just over a minute and will reveal all of the ports on your computer that have not been "stealthed" i.e. rendered invisible, so that any computer trying to open ports on your machine's IP address would get no reply.

More information on firewalls available at these links:

• Help Keep Your Computer Safe Using Windows Firewall
• Firewall Questions for beginners - Wilders Security Forum
• How Firewalls Work
• Port Forward - Free Help setting up your Router or Firewall
• Download Comodo Free Firewall ( recommended for beginners)
• Comodo Tutorials, Set-up Instructions, Frequently Asked Questions, etc
• Download Zone Alarm Free
• ShieldsUp Firewall Leakage Tester

PLEASE NOTE - I DO NOT OFFER FREE SUPPORT for these programs

I have no affiliation with the program maker and cannot vouch for or guarantee the results you may experience. Iif you choose to use them you do so at your own risk!